1j. Controlling bovine TB in the UK by controlling badger numbers
Submitting InstitutionsUniversity of Edinburgh,
Unit of AssessmentAgriculture, Veterinary and Food Science
Summary Impact TypePolitical
Research Subject Area(s)
Medical and Health Sciences: Medical Microbiology
Summary of the impact
Impact: Policy and public engagement: Formulation of the UK
government's badger culling policy for the control of bovine tuberculosis
that is currently being implemented. The underpinning research also had
wider impact in terms of generating significant public debate and
enhancing public engagement.
Significance: DEFRA has estimated the cost of TB control in
England at £1 billion over the next 10 years without taking further
action, and the cost of TB breakdown on a farm at £34,000
Beneficiaries: Livestock Industry (Cattle farms), Consumers,
Attribution: Work performed by Professor Morrison (University of
Reach: The immediate reach is the UK.
Following the identification of infection with M. bovis in
badgers in the 1970s, localised culling of badgers on TB-affected farms
was deployed by Government as an additional measure to control
tuberculosis in cattle. Despite these measures and continued intensive
application of cattle herd testing for TB, the number of cattle herds
infected with M. bovis has increased progressively over the last
In 1997, the Krebs review [3.1] recommended that Defra conduct a badger
culling trial to establish the contribution that badgers make to bovine
tuberculosis and to determine the impact of different culling strategies
on the incidence of TB in cattle. This led, in 1998, to the initiation of
a National Badger Culling Trial and a series of associated research
projects, to test the effects of different culling protocols on the
incidence of cattle TB and on the transmission dynamics of infection in
culled areas. The trial was initiated in 1998 and completed in 2006.
An Independent Scientific Group headed by Professor Morrison (Professor
of Immunology and Group Leader, UoE employed 2002-onwards) oversaw the
design and implementation of the trial and the analysis and interpretation
of the results, which were published in a number of refereed publications
[3.2-3.6] and in a final report (2007 [5.1]). Members of the independent
scientific group were: John Bourne (retired - previous IAH director),
Professor Sir David Cox (University of Oxford), Professor Christl
Donnelley (Imperial College), Professor Rosie Woodroffe (University of
California, Davis), Professor George Gettinby (University of Strathclyde)
and Professor John McInerney (University of Exeter).
The results revealed the following key findings:
- Results from proactively culled areas confirmed that badgers are a
significant source of infection for cattle, which has not been
demonstrated previously in a controlled manner.
- Culling of badgers only on farms affected with TB resulted in an
increased incidence of infection in herds within the regions subjected
to such culling.
- More extensive "proactive" culling on all farms across areas of
approximately 100 km2 significantly reduced the incidence of
infection in cattle in the culled areas, but resulted in an increased
incidence in immediately surrounding areas over the first three years,
thus partially negating the overall impact of culling.
- Culling of badgers led to disruption of their territorial behaviour,
resulting in more extensive movement into neighbouring territories.
- The residual disrupted badgers showed in increased incidence of
infection compared to unperturbed populations.
- The perturbation of badger populations subjected to culling
facilitates increased transmission of infection both between the
residual badgers and from badgers to cattle.
- Culling of badgers can only have a beneficial effect on cattle TB if
applied intensively over large areas and sustained for prolonged periods
- Previous badger culling policies are unlikely to have any beneficial
effect and may have enhanced transmission of infection.
References to the research
3.1 Krebs, J. R., Anderson, R., Clutton-Brock, T., Morrison, I., Young,
D. and Donnelly, C. (1997). Bovine tuberculosis in cattle and badgers.
Report by the Independent Scientific Review Group, MAFF Publications,
London, pp. 1-191. http://www.bovinetb.info/docs/krebs.pdf
3.2 Donnelly, C. A., Woodroffe, R., Cox, D. R., Bourne, J, Gettinby, G.,
Le Fevre, A. M, McInerney, J. P. and Morrison W. I. (2003). Impact of
localized badger culling on tuberculosis incidence in British cattle.
Nature 426, 834-837. http://dx.doi.org/10.1038/nature02192
3.3 Donnelly, C.A., Woodroffe, R., Cox, D.R., Bourne, F.J., Cheeseman,
C.L., Gao Wei, Gettinby, G., Gilks, P., Jenkins, H., Johnston, W.T., Le
Fevre, A.M., McInerney, J.P. and Morrison, W.I. (2006). Positive and
negative effects of widespread badger culling on tuberculosis in cattle.
Nature 439, 843-846. http://dx.doi.org/10.1038/nature04454
3.4 Woodroffe, R., Donnelly, C.A., Jenkins, H.E., Johnston, W.T., Cox,
D.R., Bourne, F.J., Cheeseman, C.L., Delahay, R.J., Clifton-Hadley, R.S.,
Gettinby, G., Gilks, P. Hewinson, R.G. McInerney, J.P. and Morrison, W.I.
(2006). Culling and cattle controls influence tuberculosis risk for
badgers. Proceedings of the National Academy of Sciences USA 103,
3.5 Jenkins H. E., Woodroffe R., Donnelly C.A., Cox D.R., Johnston W.T.,
Bourne F.J., Cheeseman, C.L., Clifton-Hadley R.S., Gettinby, G., Gilks P.,
Hewinson R.G., McInerney J.P., Morrison, W.I. (2007). Effects of culling
on spatial associations of Mycobacterium bovis infections in
badgers and cattle. Journal of Applied Ecology 44, 897-908. http://dx.doi.org/10.1111/j.1365-2664.2007.01372.x
3.6 Jenkins H.E., Morrison W.I., Cox D.R., Donnelly C.A., Johnston W.T.,
Bourne F.J., Clifton- Hadley R.S., Gettinby, G., McInerney J.P., Watkins
G.H., Woodroffe R. (2008). The prevalence, distribution and severity of
detectable pathological lesions in badgers naturally infected with Mycobacterium
bovis. Epidemiology and Infection 136, 1350-1361. http://dx.doi.org/10.1017/S0950268807009909
Details of the impact
The major impacts of this research are the influence on government policy
and the impact on public debate. Based on the data from this research
[5.1], the Government developed a new badger culling policy based on
extensive culling of badgers in areas with a high incidence of bovine TB,
which is now being implemented. This was developed in partnership with the
farming community, which will bear most of the cost. Details of the
implementation of the badger culling are available on the Defra web site
While the research has allowed the design of culling policies that are
predicted to have a beneficial effect on the bovine TB problem if properly
implemented, it has also highlighted the shortcoming of this approach as a
stand-alone option. Indeed, the evidence of the extent of culling that is
required to produce any substantial impact has hardened opposition to
culling by numerous community groups. An example is a recent decision to
ban badger culling on Council land [5.3]. Equally, the research has had a
major impact on public debate around badger culling [5.4-5.6]
The research and the intense public debate have subsequently influenced
the UK government to redirect resources to alternative control measures.
These include development of badger TB vaccination, which has received
increased funding from Defra over the last 5-10 years, with plans in place
to develop a bait-delivered vaccine that could be applied to large
populations of badgers [5.7].
A second approach is based on the recent demonstration that resistance to
TB in cattle is a heritable trait (5.8). At its May 2013 board meeting,
DairyCo agreed to fund genetic evaluation of dairy bulls in the UK for TB
Sources to corroborate the impact
5.1 Bourne F.J., Cox D.R., Donnelly C.A., Gettinby G., McInerney J.P.,
Morrison W.I. and Woodroffe R. (2007). Bovine TB: The Scientific Evidence:
A Science Base for a Sustainable Policy to Control TB in Cattle. Final
Report of the Independent Scientific Group on Cattle TB. Defra
Publications. Pp.1-289. http://tinyurl.com/qb4qxq7
5.2 Defra News, Bovine TB. http://tinyurl.com/ohhfjeq
5.3 Buxton Advertiser, "Council bans badger cull on county land" http://tinyurl.com/oktty9k
5.4 Farmers Guardian, "Farming hot topic : Bovine TB" http://tinyurl.com/nfhntz7
5.5 The Wildlife Trusts, "Badgers and bovine tuberculosis" http://tinyurl.com/om2pswv
5.6 UK Parliament, Opposition debate on the badger cull http://tinyurl.com/qcykpwg
5.7 Defra, Badger Vaccination http://tinyurl.com/q954hw7
5.8 Allen AR, Minozzi G, Glass EJ, Skuce RA, McDowell SW, Woolliams JA,
Bishop SC. Bovine tuberculosis: the genetic basis of host susceptibility
Proc Biol Sci. 2010 Sep 22;277(1695):2737-45. http://dx.doi.org/10.1098/rspb.2010.0830.
5.9 DairyCo Meeting Minutes May 2013 http://tinyurl.com/qjctkxq